A POS (Point Of Sales) terminal well-known as a commodity sales data processing apparatus is generally of a stationary type and is formed by mounting input/output devices, such as a keyboard, a display, a printer and the like, on a main body carrying a control unit.
In recent years, a portable information terminal carrying a touch panel, namely a tablet-type information terminal, has been popularized. If a POS terminal is formed with such an information terminal, for example, the sales data of a commodity purchased by a customer can be registered while service for customers is offered at the sales floor. This is very convenient for both customer and shop clerk. However, it is not preferable to execute, except a registration function within functions of the POS terminal, an inspection function, a settlement function and a journal retrieval function with such a portable information terminal which can be used at any location on the sales floor in view of an information security because confidential information of a store is required at the time such functions are executed.